An agricultural harvester, such as a windrower or combine, is a large machine used to harvest a variety of crops from a field. In the case of a combine, during a harvesting operation, a header at the front of the combine cuts ripened crop from the field. In the case of thinner stemmed crops such as soybeans, wheat, etc. which may be cut with a sickle bar carrying a plurality of knives, the header may also be known as a cutting platform. A feederhouse supporting the header transfers the crop material into the combine. Threshing and separating assemblies within the combine remove grain from the crop material and transfer the clean grain to a grain tank for temporary holding. Crop material other than grain exits from the rear of the combine. An unloading auger transfers the clean grain from the grain tank to a truck or grain cart for transport, or to another receiving bin for holding.
In the case of a windrower, during a harvesting operation, a header at the front of the windrower cuts ripened crop from the field. The crop is transported to the rear of the header and forming shields form a windrow of the crop between the tires of the vehicle for natural dry down of the crop. A subsequent field operation picks up the windrows for further processing, such as separating and cleaning in the case of grain crops, or baling or chopping in the case of hay.
A cutting platform may generally be of two types. One type typically has a sheet metal floor with a dual feed auger near the rear of the cutting platform for feeding the crop material longitudinally to the feeder housing. A cutting platform of this type with auger feed is more common.
Another type of cutting platform, also known as a draper platform, utilizes a flat, wide belt, referred to as a draper or draper belt to convey crop material. The arrangement and number of belts vary among platforms. One style of draper platform used on a combine has two side belts that convey crop material longitudinally, to the center of the platform, where a center feed belt moves the crop material laterally into the feeder housing. Each belt is wrapped around a pair of rollers, one being a drive roller and the other being an idler roller. An example of this type draper arrangement is disclosed in U.S. Pat. No. 6,202,397, which is assigned to the assignee of the present invention.
An advantage of a draper platform is that larger amounts of crop material can be transported without plugging, etc. For example, with wide platforms approaching 40 feet or even larger, the amount of crop material transported to the feeder housing can be substantial. With an auger feed platform, the crop material may bind between the auger and the back wall of the platform. In contrast, with a draper platform, the crop material is carried on top of the belt with less chance for plugging.
With wider draper platforms from 25′ to 40′ as described above, controls are provided to allow an operator to finely tune the speeds of the draper belts, reel and cutter bar based on the particular crop and operating conditions.
Typically when windrowing a field the operator will use one of two methods. One method is to make a few passes around the field and then cut back and forth laying the windrows parallel to each other. The second method is to cut around the field in one direction working from the outside in. Generally the corners are made square by cutting out, picking up the header (avoiding dragging it through a crossing windrow), turning around and lowering the header before entering crop.
When a row is completed and the head pulls out of crop it takes a moment for the belts to unload the crop into the windrow. The operator generally raises the head and reduces ground speed to insure the windrows don't overlap. If the operator does not pause and let the draper belts unload before crossing another windrow, the windrows overlap and are very difficult to pick up with a combine.
What is needed in the art is a draper cutting platform that can be operated in an end-of-row condition such that the crop does not cross windrows.